Studies were directed toward determining the sequential steps involved in the differentiation of lymphocyte B-cells to immunoglobulin synthesizing and secreting cells. The study was conducted to determine the normal rates of synthesis, transport and catabolism of the plasma proteins, especially the immunoglobulins, to determine the physiological factors controlling these metabolic parameters and to determine the pathophysiology of disorders of plasma protein metabolism in patients with neoplastic disease and in patients with hereditary disorders of immunoglobulin metabolism. Developing techniques for the detection of circulating tumor-related antigens has also been an object of study.